Heat oven to 425 degrees.
Prepare your crust in 9-in pie pan. Set aside.
1 9-inch pie crust
Saute mushrooms, and onions in butter until tender and just slightly golden. Reserve a few mushrooms to place on top of quiche. Set mushrooms and onions aside.
1/2 sliced mushrooms, 1/3 cup chopped onion, 1 teaspoon butter
Cook broccoli until al dente (use your preferred method since it's such a small amount. You can use the microwave with a few tablespoons of water, or steam on the stove top. If using frozen broccoli, heat per directions on package.) Set aside.
1 cup chopped and cooked broccoli
In medium-sized mixing bowl whisk together eggs, cream, salt, and pepper.
4 eggs, 2 cups heavy whipping cream, 1/4 teaspoon salt, 1/4 teaspoon pepper
Mix in cheese.
1 cup shredded Swiss cheese
Stir in broccoli.
1 cup chopped and cooked broccoli
Add mushrooms and onions. Stir
Pour mixture into prepared pie pan. Place reserved mushroom slices on top for decorative touch.
1/2 sliced mushrooms
Bake 15 minutes. (If crust is browning too quickly, place foil around edges of crust)
Reduce heat to 300, bake 30 more minutes until knife inserted into center of quiche comes out clean.
Let cool for 10 minutes before slicing.